The popularity of dune buggies, or similar all-terrain vehicles has swelled in past years. These types of vehicles are typically four-wheeled, open frame vehicles powered by a small motor and having a conventional transmission.
Similarly, the popularity of "trikes," or three-wheeled open air vehicles, for leisure use has grown. These trikes are similar to their four-wheeled counterparts, except that they have three wheels, and are typically used for on-road applications.
In both cases, several engine and transmission combinations have been devised for use in powering these vehicles. By far, one of the most popular has been the use of the engine and transmission combinations manufactured and sold under the name Volkswagen or "VW" VW engines and transmissions, adopted from the popular VW "Bug" or "Beetle" cars, have several advantages. First, the extreme popularity of these automobiles has led to the great availability of original and replacement engines, transmissions, and related parts. Second, these engines are extremely reliable, rugged, and are fairly light-weight. Lastly, these engines are air-cooled, eliminating the need for costly and complicated liquid cooling systems.
The VW engines used in these sport vehicles are of a 4 cylinder variety, and range in size from 1300 to 1800 cc. The most common VW transmissions employed are the Type 1 Transaxles, a 4 speed transmission with reverse.
Lately, several alternatives to the use of the VW engine and transmission combination have been explored. One option is the substitution of a motorcycle engine manufactured by Harley-Davidson Co. for the VW automobile engine. In particular, the Harley-Davidson V-twin 80 C.I.D. engines manufactured from 1980 to the present have been deemed suitable for use in dune-buggies and "trikes."
These Harley-Davidson engines have the advantage that they are air-cooled, are light-weight, and offer higher horsepower-to-weight and torque-to-displacement ratios than stock VW automobile engines.
On the other hand, the transmissions used on the Harley-Davidson motorcycles are not suitable for use on dune-buggies or "trikes." Therefore, it has been found desirable to power the vehicle with a combination of a Harley-Davidson engine coupled to the VW transaxle. Unfortunately, before the present invention, no simple, reliable means has been devised for coupling these Harley-Davidson engines to the VW transaxles.